I would not be too worried, there really is a lot of individual variation in responses to GLP medications. For most people using them it is to help with a lifelong or at least long term problem with weight, so you are talking about taking them for years to forever, a few weeks is not going to make a big difference.
If you have zero effects and zero side effects, then increasing the dose more rapidly is an option, ( assuming you are not elderly or diabetic or have multiple serious medical issues ) but I would stick with the twice a week dosing, so that when or if you overshoot your tolerance to it and suddenly feel nauseous for example , it will not take as long for your blood levels to get back to where they were, than if you were using twice the dose half as often.
The risk of increasing doses more frequently is that it takes 24 to 48 hours for a dose to be absorbed, then a week to drop back to half what it was. This is totally different to nearly any other drug used for anything, is not intuitively obvious and so the same dose can take up to 4 weeks to reach maximum effect as it slowly builds up in your bloodstream. I would highly recommend the
https://glp1plotter.com/ website so you can see what different doses and schedules do to blood levels.
Bumping your next dose up to 1mg and leaving it there for a couple of weeks is likely to be fine, , if you have zero effects before that dose, but increasing the dose too often or too much runs a very high risk of suddenly having a whole lot of horrible side effects, which might take a week to subside. Side effects are also very variable but the most common ones are nausea, vomiting , diarrhoea, constipation, and unpleasant skin sensations. Vomiting for a week is not going to be fun, and would definitely need medical treatment or maybe even hospital so you need to be very careful if you try this, or just be patient and wait which is much safer. Generally side effects are easier to tolerate if they build up slowly from a low level rather than hit like a ton of bricks, which is the basic reason for the whole start at a low dose and very slowly build it up dosing regime for GLP medications.
It is possible that your reta is not reta or empty of active drug, but it really is pretty rare for this to happen, but unless your exact batch got tested independently there is no way to be sure. Assuming you bought it from one of the popular sellers advertising on the glp forum, and not via some random tiktok seller, I would guess the odds are less than one in a thousand, and it is far more likely that you are just not that sensitive to low doses of reta. If you are still having zero effects from 4 mg/week or so then I would start getting suspicious.
